If it is now shifting OK , just keep the ATF clean and fresh and don't worry too much.
If you tow a trailer or drive really hard or carry a LOT of weight, then think about a tranny cooler. I don't have one on mine.
It is pretty easy to do an ATF drain and fill yourself and quite a few, including myself, use the lower cost Valvoline MaxLife Dex/Merc ATF with great results.
Damn, I wish my '03 looked that clean!!!! Wow! 😅
I have approx 216k miles on mine and I still have the original tranny. I had a timing belt service done about 5k miles ago and also changed the original alternator (used a rebuilt Denso) just for less worry.
If your Ody is mechanically in anywhere in as good of shape as it looks, you will really enjoy it.